There have been known door open-close systems configured to detect a leg motion and automatically open a vehicle door even when a vehicle user carries baggage with both hands. For example, JP 2014-500414 W discloses a door open-close system including first and second sensors disposed at different sites at a vehicle rear portion and configured to detect a leg motion.
FIGS. 16 and 17 are views depicting disposition of the sensors according to JP 2014-500414 W. FIG. 16 is a rear view of a vehicle 100 whereas FIG. 17 is a side view of the vehicle 100. The vehicle 100 includes a vehicle body 1, a rear door 2, a rear bumper 3, a rear window 4, tires 5, a first sensor 60, and a second sensor 70.
The first sensor 60 is disposed at the rear bumper 3 whereas the second sensor 70 is disposed at the bottom of a rear portion (in a B direction) of the vehicle body 1. The sensors 60 and 70 each have a long and narrow detection area extending in a Y direction. These detection areas are disposed spaced from each other. The detection area of the first sensor 60 projects beyond the detection area of the second sensor 70 at the ends in the Y direction.
The door open-close system detects a time difference between an output signal from the first sensor 60 and an output signal from the second sensor 70. If the time difference satisfies a predetermined criterion, the door open-close system determines that a leg 6 has executed a kicking motion to insert the tip end of the leg 6 between the vehicle body 1 and a ground surface G as depicted in FIG. 17, regards the motion of the leg as a command to open the door, and opens the rear door 2. If the time difference does not satisfy the predetermined criterion, the door open-close system determines that the motion of the leg 6 does not correspond to a command to open the door, and does not open the rear door 2. This configuration thus prevents erroneous detection.
As apparent from FIG. 17, the second sensor 70 is disposed at a far portion (in an F direction) of the bottom of the vehicle body 1 with respect to the first sensor 60 in the door open-close system according to JP 2014-500414 W. The second sensor 70 can thus be restrained in terms of its mounting position.
Meanwhile, JP 2014-9470 A discloses a door open-close system configured to determine, when detecting a user in a detection area around a rear door, whether or not its detection pattern corresponds to a preliminarily set detection pattern, and open the rear door if the detection pattern corresponds to the preliminarily set detection pattern.
This door open-close system has a plurality of detection areas and detects the user in each of the detection areas so as to be distinguishable between these detection areas. According to the detection pattern thus set, the user is detected in a preliminarily set order of the detection areas. The door open-close system is configured to open the rear door only in a case where the user is detected in the predetermined order of the detection areas and thus prevents erroneous detection.
However, the door open-close system according to JP 2014-9470 A needs to have a plurality of detection patterns that cover user's behavior as well as a control program that covers these detection patterns. The door open-close system is thus complicated in its design and processing. The door open-close system also needs to include a high capacity memory configured to store these patterns and program.